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Avatar universal

Understanding my thyroid lab results

So I've basically been through hell the last three months. But long story short I was put on 137mcg of levotheroxine by an  endo and was on this dose for the longest time. Still expereincing some brain fog, My primary care physician switched me to 75mcg of Cytomel (t3) once a day for 3-4months. The Brian fog got ten times worse  and i literally felt like i was only running on adrenaline (extreme fatigue) and the symptoms only seemed to get worse as a time went on. I begged my PCP to run my labs again.  So I desperately went back to that same endo and she put me on 112mcg (t4 once a day) and 10mcg (t3) twice a day and she told me that it's not a good idea to run that amount of T3 especially only once a day..

My lab numbers were
T4 1.0 range 5-12 ug
T3 187 range 80-200 ng
Tsh 2.2 range .27-42

I understand that aking t3 alone that the t4 levels would drop, but does T4 matter at all if you're getting enough T3 and your tsh is in normal range?? Looking for advice thanks so much..
10 Responses
Avatar universal
Just to be sure, when was the blood draw for those labs in relation to your med changes?

Also what were your symptoms and lab test results when originally diagnosed?  

When you were on the 137 mcg of Levo did you have symptoms other than "brain fog"?

Your PCP obviously doesn't understand about hypothyroidism.  Switching you  from 137 mcg of T4 to 75 mcg of T3 effectively almost doubled your med.  On top of that, T3 reaches peak effect on serum levels in about 3-4 hours, so the usual approach is to split the dose and take half in the morning and half in the afternoon in order to smooth out the effect over a longer period.   Because of that it is also a good idea to defer morning dose until after blood draw for any thyroid testing, in order to avoid false high results.  

And yes, T4 levels matter.  T4 is converted to T3 to be metabolized in cells throughout the body.  Reserves of T4 circulating throughout the body is available for conversion as needed throughout the full day.    I am also sending you a PM with a link to info on the effects of taking T3 med only.
Thank you Gimel for your response, yes the blood work in direct correlation with the 50mcg of t3. My symptoms were extreme fatigue and brain fog. Don't remember my labs when I was initially diagnosed because it was 2010. But my tsh was at 4.14 in 2013 when I was taking 112mcg of t4.
Looking back I can't believe I let
My PCP change my dose. When I went back to the endo she was shocked I was on T3 only. She said that if I took the medication at 6 AM by Noon I was basically  running on adrenaline rest of the day.
He kept me on T3 and started to think maybe it was something else. He tried me on ADHD medication which was terrible,  and he put me on Lexapro for seven weeks and only made things worse. He even had me doing EEG scan, and of course nothing showed up. I decided to go back to my Endo because I truly felt it was a hormone related issue.
  So now I'm on 112 MCG's of T4 and 10 MCG's of t3 twice a day.i'm worried since t3 goes through the body quick and right now I basically have no t4  in my body that's its going to be a rough few weeks into the T4 medication starts kicking in. I was on on 75mcg of T3 for 30weeks. I'm just Open to get back to where I was.
Avatar universal
Okay, so you are headed back in the right direction.  What you should be looking for is to raise your med doses as needed to get to are Free T4 at mid-range at least, and Free T3 in the upper part of its range, or as needed to relieve hypo symptoms.  So you should make sure they always test for both Free T4 and Free T3, not Total T4 and T3, like shown above.  The Totals represent all that is in your blood.  Most of that is tied to protein and biologically active.  Only the small portions that are free of protein are active.  Also, don't forget to defer your morning dose of med until after blood draw, to avoid false high results.  

In addition it would be a good idea to test for Reverse T3, just to know that level.  Reverse T3 is a mirror image of T3, but biologically inactive.  Reverse T3 is a normal result of conversion of T4 to T3, but under some adverse conditions excess Reverse T3 is produced and it interferes with Free T3.  Also, since hypo patients are so frequently low in the ranges for Vitamin D, B12 and ferritin, it would be good to test those and supplement as needed to optimize.  I don't know about your ability to get the doctor to test for you, but if at all possible I would also ask for a morning serum cortisol test.

If you want more info on this and also something you can use for discussion with your doctor have a look at this link.  

Thank you again, it's getting to the point where I'm questioning if it's only my thyroid. I literally can't think, it's like someone opened my head a took my brain out. My thought process is simply not there. I know my thyroid had been way off for the last 6 months. I am tired and and I am not seeing the things visually like I did 6 months ago. I'm hoping this is all from my thyroid
Avatar universal
There is an old saying, "If it walks like a duck and quacks like a duck it most likely is a duck."   With your symptoms and lab results and history of meds and dosages,  my bet would be that it is primarily a thyroid problem.  

In addition since hypo patients are so frequently deficient in Vitamin D, B12 and ferritin, I highly recommend testing for those and supplementing as needed to optimize.  D should be 50 min., B12 in the upper end of its range, and ferritin should be a minimum of 70.   And don't overlook testing for Reverse T3 along with your next Free T3 and Free T4 tests.  Also, I suggest the morning serum cortisol test.  
Again thank you for your response, I have been put through the ringer the last 12 weeks. I'm really dragging right now because it's only been a Week and my t3 was lowered to 10mcg twice a day and 137mcg of t4. I feel like the T4 has not built up in my system yet, therefore I'm in a constant fog with extreme fatigue, it's like nothing looks crisp and my brain just doesn't want to work. Knowing it will take a while to get my dose to the precise spot I'm hoping that progress will slowly help alleviate some of the symptoms.
Avatar universal
Did the doctor give you an alternative of staying at a higher dose of T3 and gradually reducing the dosage until the T4 med has time to kick in?
No, endo just brought me down to 112 lev. And 10mcg t3 twice a day. I'm having such a hard time right now and I'm wondering if it was too much of a cut to soon. The brain fog is so bad right now that it affects my vision. Everything looks "off" it's hard to explain. And I can't think at all and fatigue is terrible, I literally can't leave the house. She said that not having (total t4  1.0
Of a range of 5-12) has had a serious effect on my body. I am typically up at 6 AM going to the gym first thing in the morning five days a week and now I don't have the energy to go at all. And i notice that I sweat at different times. It feels like I will never get out of this, I'm so frustrated
Avatar universal
I think the doctor needs to do something to give you some short term relief while you are rebuilding your Free T4 level.  I would try to make contact with his emergency number and relate how badly you are feeling and request to increase your T4 med significantly for a week to try and raise your level faster.  Also anything else the doctor can suggest to help in the short term.  

Since hypo patients are so frequently too low in the ranges for Vitamin D, B12 and ferritin, I would also get those tested ASAP.  D should be bout 50 min. , B12 in the upper end of its range, and ferritin should be 70 minimum.   Low levels of those can cause symptoms, especially fatigue.  

And by all means if you get to feeling too bad, don't hesitate to go to the ER.  
The larger the dose of t4 the Quicker you think I would see benefits? I had my vitamin B, vitamin D and cortisol done last weds. So I should get the blood work back on Monday. I also had testosterone and free testosterone done.  My t levels came back in around 320 last time.
I'm thinking for the next week or two I need a significant jump in T4, and if need be I can always pull back later
Avatar universal
Yes, that is what I am suggesting that you try and get your doctor to do for you:  a short term significant increase in T4 med to try and get your Free T4 normalized as soon as possible.  
Thank you for your input, I do agree I need more t4 in my body. I don't want to go the self medicated route, but I'm afraid my endo wil not agree. I'm wondering I just went to 175-200mcg for a few weeks if that would make a difference. I will call my endo tomorrow and see what she says
I'd like to make a couple of suggestions.

First, keep in mind that a normal thyroid will produce about 90 - 100 mcg of T4 and about 6 mcg of T3 in a day. So your daily intake should somewhat similar, and also take into account that you do not absorb 100% of your meds.

So you can see that your 112 mcg T4 is in the ballpark, but your 20 mcg of T3 is quite high.

The second thing to keep in mind is that your natural thyroid would release the 6 mcg of T3 slowly over the course of a day. So your taking 10 mcg T3 at a time is not mimicking nature very well because the T3 gets into your bloodstream very quickly. It is possible that this is the cause of your problems.

The solution is to use compounded slow release T3. Find a "compounding pharmacy" in your area and ask about it. They would call it Liothyronine Slow-Release Capsules and they would make the capsules to the strength that your doctor prescription specified.

I went the route of Synthroid plus slow release T3 a couple of years ago. This is the combinations that I tried and the result I got:
100 T4 + 5 T3 - free T3 too low
100 T4 + 10 T3 - free T3 too low
100 T4 + 15 T3 - free T4 slightly high
88 T4 + 15 T3 - free T3 and free T4 too low
94 T4 + 15 T3 - free T3 at 60% of range and free T4 at 40% of range. I have stayed at this for nearly two years now. I get the T3 compounded at 5 mcg each.

The third thing to keep in mind is that your natural thyroid level goes up at night; it starts to rise at about 9 pm and peaks at mid-night to 1 am. So I try to imitate nature; I take 50 mcg Synthroid plus 10 mcg T3 at bedtime, then 44 mcg Synthroid plus 5 mcg T3 before breakfast. This has the added benefit that you do not have to take it thru the day. Do not eat or drink a couple of hours before taking meds and do not eat or drink for 1/2 to 1 hour after taking meds.

Regarding whether you should take extra T4 now to get your level up. T4 is slowish to build-up in your body. After 7 days your T4 is at 50% build-up in your bloodstream; after 14 days at 75% and after 21 days at 87.5%. Multiply your dose times the percentage to get your current level; with your dose of 112 mcg T4, after 1 week your level is 56, after 2 weeks 84 and 3 weeks 98.

I would be very careful to not take too much. If you took 200 mcg T4 for one week your blood level would be up to 100. So your thought of taking 175 - 200 for a few weeks would be way too much.
Avatar universal
Thank you for your response, I made a mistake I am taking liothyronine 10mcg at night and morning  along with 112mcg levotheroxine in the morning.
I thought about switching the dose to
Night time to see if that changes anything.
After being on liothyronine for around six months straight at 75 MCG's once a day. I'm now on the 10th day of my new dosages.I know I need to stay patient but I'm trying to figure out when I will start seeing improvements in the t4 kicking in. I have a baby girl coming in a month and I'm trying to do the best at work and I just feel really pressured. It's hard for me to stay awake at all to even get off the couch. It feels like somebody reached  inside my head Out lol.  I'm not processing things nearly as fast as I usually do.
Are year ago I was on 137 MCG's of levethyroxine and felt ok and only had small symptoms. My just a small increase of my t4 would have done the trick.
Avatar universal
Jchild83     I agree with telus2 that taking that much T4 for more than a week would be too much.  

telus2       I am not clear about your numbers on daily production of T4 and T3  by a normal thyroid gland.  I find in the following that it states that, "The overall production rate of T3 per day is approximately half that of T4 (50 vs 110 nmol), and circulating levels of free T3 (FT3) are approximately 3- to 4-fold less than that for free T4 (FT4) (5 vs 20 pmol/liter)."  Also, it states that, In view of the very long circulating half-life of T4, it is probably not surprising that no circadian rhythm has been described.  Absolute circulating levels are determined by secretion as well as clearance, and because T3 has a shorter half-life, one might predict that if TSH stimulates a proportion of T3
release from the thyroid, then a circadian rhythm would be evident."


Also, in another reference it was stated that the production of  T4 was about 80% of total, while T3 was about 20%.  Since circulating levels are determined from  endogenous and/or exogenous sources as well as clearance rate, I'm not even sure how to best utilize this info.   I guess one could interpret the circadian rhythm of TSH and Free T3 in normal circumstances as indicating that there is a increase of Free T3 starting at about 10 o:clock or so as preparation for awakening.  Taking this into account would suggest that medicating at night might be best; however some people have sleep problems with that approach.  Cortisol exhibits a similar pattern to help get us out of bed.  So I think that the bottom line is that the best time to take thyroid med is whatever works best for the individual.  Since I do struggle with awakening early, I think I will try taking a small portion of my T3 med at night just to see if it makes a difference for me.

With all the variables, it seems that the key thing is to get Free T4 and Free T3 levels high enough to relieve hypo symptoms, without creating any hyper symptoms.  Those levels have been shown to be different among different people.   Serum thyroid levels may not accurately reflect tissue thyroid levels due to thyroid hormone transport into the cells being affected by many variables.  And of course thyroid hormone at the cellular level is even affected by levels of Vitamin D, cortisol and even TSH.   So the resulting tissue thyroid effects (symptoms) may vary widely for the same serum thyroid levels of Free T4 and Free T3.  So the paramount objective must always be the relief of symptoms, not specific dosages or serum levels.  

When you were varying your med dosage, how did you determine if levels were too low or too high?  

It has always seemed to me that the very best possible med for hypo patients would be timed release type containing both T4/T3 in natural proportions.  Unfortunately that doesn't exist at present and I have heard of no efforts to develop such a med.  I had not even heard previously of anyone  having a timed release T3 med that worked adequately.  So, I am glad to hear of your success with timed release T3 from at least your source anyway.
Avatar universal
You Guys of been really helpful, my doctors in the past just went by tsh levels which I know now doesn't tell the whole story. I've never felt nearly as bad  as I do now. From what I've read 75mcg of t3= 300mcg of t4 which is more than double what I was taking. I'm just hoping my endo has me on the right path now with getting my back on t4. I can't live like this, I can't think and inconatantly feel dizzy.
Avatar universal
Just for info, there are a couple of scientific studies that say the correct factor is 3 to 1, not 4 to 1.  
Ok, I am just hoping to see some progress soon. I think taking the t3 it basically shut down my t4 for almost 6 months. I wish there I could see some light at the end of the tunnel. All of this has impacted my brain function and my vision.  Again it's nice just to talk about these things with people.
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